Multi-Omic Profiling and Functional Validation Identify an NF-κB-Centered Pro-Survival Network Underlying Resistance to Oncolytic VSV in Prostate Cancer Cells

The therapeutic efficacy of oncolytic viruses is often limited by tumor cells that resist virus-mediated killing. Here, we investigated the molecular mechanisms underlying resistance to Vesicular Stomatitis Virus (VSV) in PC3 cells, an aggressive, metastatic prostate cancer cell line, using the VSV-sensitive LNCaP cell line as a comparator. RNA sequencing revealed that, relative to untreated cells, VSV-infected PC3 cells upregulated both pro-apoptotic genes, including BIM, PUMA, and NOXA, and anti-apoptotic and antiviral genes, including A20 and RIG-I. In addition, genes associated with antiviral and pro-survival pathways, including NF-κB and PI3K-Akt signaling, were more highly expressed in PC3 cells than in LNCaP cells. At baseline, PC3 cells also exhibited elevated expression of pro-survival genes, including BCL-xL, MCL1, and CK2, compared to LNCaP cells. Complementary phospho-protein array analyses identified increased phosphorylation of proteins associated with NF-κB, PI3K-Akt, and MSK1 signaling in VSV-infected PC3 cells relative to infected LNCaP cells. Furthermore, pharmacological inhibition of BCL-2 family proteins or NF-κB signaling sensitized PC3 cells to VSV-induced cell death. These findings support a model in which NF-κB-centered pro-survival signaling networks contribute to the resistant phenotype of PC3 cells and suggest that combining oncolytic virotherapy with targeted inhibitors may improve therapeutic efficacy in resistant prostate cancers.